Coating method and apparatus for semiconductor process

ABSTRACT

A coating apparatus has a spin chuck for attracting and holding a semiconductor wafer in a horizontal state by means of vacuum. A movable beam is arranged above the spin chuck. The movable beam includes first and second nozzles integrally formed. The first nozzle is used for supplying a photo-resist liquid while the second nozzle is used for supplying a solvent for the photo-resist liquid. When a coating process is performed, the movable beam above the wafer is horizontally moved in one direction. The solvent is first supplied onto the wafer from the second nozzle, and the coating or photo-resist liquid is then supplied from the first nozzle, following the solvent. Wettability of the wafer relative to the photo-resist is increased by the solvent, prior to supply of the photo-resist liquid.

This application is a division of application Ser. No. 08/919,503, filedon Aug. 28, 1987, now U.S. Pat. No. 5,919,520

BACKGROUND OF THE INVENTION

The present invention relates to a coating method and apparatus for asemiconductor process, and, in particular, to a method and apparatus forcoating a target substrate, such as a semiconductor wafer or an LCDsubstrate, with a coating liquid, such as a photo-resist liquid or adeveloping liquid. The semiconductor process includes various kinds ofprocesses which are performed to manufacture a semiconductor device or astructure having, for example, wiring layers and electrodes to beconnected to a semiconductor device on a target substrate, such as asemiconductor wafer or an LCD substrate, by forming semiconductorlayers, insulating layers, and conductive layers in predeterminedpatterns on the target substrate.

In a process of manufacturing a semiconductor device or an LCD, coatingapparatuses are utilized in various steps. A representative one of themis a coating apparatus of a photo-resist liquid, employed in a coatingand developing system of the photo-resist. The photo-resist liquid isapplied onto a target layer to be pattern-etched, such as asemiconductor, insulating, or conductive layer on a semiconductor, so asto form a photo-resist film on the target layer. The photo-resist filmis exposed to light through a predetermined mask and is developed sothat the film is patterned to copy the mask. Then, the target layer isetched, using the patterned photo-resist film as a mask.

Jpn. Pat. Appln. KOKAI Publication Nos. 7-8879, 7-8880, 7-8034, 7-80385,and 7-80386, and Jpn. U.M. Appln. KOKAI Publication No. 7-31168 disclosea coating method of a certain type for applying a photo-resist liquid.In this coating method, a target substrate and a nozzle for deliveringthe photo-resist liquid in a band shape are moved relative to each otherin a direction perpendicular to the band of the photo-resist liquid, sothat the top surface of the target substrate is coated overall with thephoto-resist liquid.

However, this method entails the following problems. First, since asolvent contained in the photo-resist liquid is evaporated while theliquid is applied onto the target substrate from its one end to theother, there is a difficulty in forming a thin film, and the necessaryamount of the photo-resist liquid is relatively large. Further, as shownin FIG. 8, more photo-resist liquid is applied at the start and endpoints of the coating process, thereby bringing about a difficulty informing a film having a uniform thickness. Furthermore, the surface ofthe target substrate occasionally has a bad wettability relative to thephoto-resist, depending on the properties of the surface, therebybringing about difficulties in forming a film having a uniform thicknessand in performing a process with a small amount of the photo-resistliquid.

BRIEF SUMMARY OF THE INVENTION

An object of the present invention, therefore, is to provide a coatingmethod and apparatus for a semiconductor process, which can form acoating film having a uniform and thin thickness, and can decrease thenecessary amount of a coating liquid.

According to a first aspect of the present invention, there is provideda coating method for a semiconductor process, of coating a target regionof a substrate with a coating liquid, comprising:

a pre-coating step of coating the target region of the substrate with asolvent for the coating liquid, by supplying the solvent onto the targetregion from a solvent supply port while supporting the substrate by asupport which supports the substrate substantially horizontal; and

a main coating step of coating the target region of the substrate withthe coating liquid after the pre-coating step, by supplying the coatingliquid onto the target region from a coating liquid supply port whilemoving the substrate supported by the support and the coating liquidsupply port relative to each other in a first direction.

According to a second aspect of the present invention, there is provideda coating apparatus for a semiconductor process, for coating a targetregion of a substrate with a coating liquid, comprising:

a support for supporting the substrate substantially horizontal;

a solvent supply port for supplying a solvent for the coating liquidonto the target region of the substrate supported by the support;

a coating liquid supply port for supplying the coating liquid onto thetarget region of the substrate supported by the support; and

first sifting means for moving the substrate supported by the supportand the coating liquid supply port relative to each other in a firstdirection.

In the present invention, a coating liquid is supplied after wettabilityof the surface of a target substrate is enhanced relative to the coatingliquid, so that the coating liquid is not repelled even if its amount issmall, thereby forming a coating film having a uniform and thinthickness. Further, since the coating liquid can be supplied in anoptimum mixing ratio relative to a solvent when the coating film isformed, the necessary amount of the coating liquid to be used isdecreased. Furthermore, since the solve and the coating liquid arebrought into contact and mixed with each other, it is possible to causethe coating liquid to have a uniform viscosity and to prevent bubblesfrom being produced in the coating liquid.

Additional objects and advantages of the invention will be set forth inthe description which follows, and in part will be obvious from thedescription, or may be learned by practice of the invention. The objectsand advantages of the invention may be realized and obtained by means ofthe instrumentalities and combinations particularly pointed out in theappended claims.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate presently preferred embodiments ofthe invention, and together with the general description given above andthe detailed description of the preferred embodiments given below, serveto explain the principles of the invention.

FIG. 1 is a perspective view schematically showing a coating apparatusaccording to an embodiment of the present invention;

FIG. 2 is a structural view schematically showing the coating apparatusshown in FIG. 1;

FIG. 3 is a cross-sectional view showing a nozzle-waiting section of thecoating apparatus shown in FIG. 1;

FIG. 4 is a side view schematically showing the main part of a coatingapparatus according to another embodiment of the present invention;

FIG. 5 is an enlarged view for explaining the function of the structureshown in FIG. 4;

FIGS. 6A and 6B are cross-sectional views each showing a modification ofa movable beam, which constitutes nozzles for respectively supplying acoating liquid and a solvent;

FIG. 7 is a perspective view showing a coating and developing systemhaving the coating apparatus shown in FIG. 1; and

FIG. 8 is a graph showing a distribution in a photo-resist filmthickness according to a conventional method of forming a photo-resistfilm.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a perspective view schematically showing a coating apparatusaccording to an embodiment of the present invention. The coatingapparatus 1 is constituted to coat a semiconductor wafer W with aphoto-resist liquid.

As shown in FIGS. 1 and 2, the coating apparatus has a holder, such as aspin chuck 10 for attracting and holding a target substrate, i.e., asemiconductor wafer W, in a horizontal state by means of vacuum. Amovable beam 20 is arranged above the spin chuck 10 such that it can bemoved in an X direction by a scanning mechanism 40 from one end of thewafer W to the other end. The movable beam 20 constitutes first andsecond nozzles 21 and 22 which are integrally formed. The first nozzle21 is used for supplying a photo-resist liquid, i.e., a coating liquidBL, while the second nozzle 22 is used for supplying a solvent AL forthe photo-resist liquid. The first and second nozzles 21 and 22 areconnected to a tank 25 of the coating liquid BL and a tank 26 of thesolvent 26, respectively.

More specifically, the spin chuck 10 is arranged horizontal in a cup 12and at the upper part of a box-like apparatus body 60. Suction holesconnected to a vacuum device (not shown) are opened on the top surfaceof the spin chuck 10, so that the wafer W can be attracted and held onthe spin chuck 10. The spin chuck 10 is rotated in a horizontal plane bya motor 14 arranged in the apparatus body 60, and is moved in a verticaldirection by an elevating cylinder (not shown) arranged in the apparatusbody 60. A waiting section 70 is arranged on the apparatus body 60 andapart from the spin chuck 10, for the movable beam 20 to wait at.

The movable beam 20 is formed of a hollow body of, for example, astainless steel or aluminum alloy. The inside of the movable beam 20 ispartitioned along its longitudinal direction by a partition wall 29, sothat it is divided into two independent rooms, i.e., first and secondrooms 27 and 28 arranged on the back and front sides, respectively, in adirection in which the beam 20 is moved during a coating process. Thefirst and second rooms 27 and 28 function as reservoirs of the first andsecond nozzles 21 and 22 for supplying the coating or photo-resistliquid BL and the solvent AL, respectively.

A slit 21 a is formed to extend in a longitudinal direction of the beam20, i.e., in a Y direction perpendicular to the X direction in which thebeam 20 is moved, such that the slit 21 a communicates with the firstroom 27 and is opened downward. Similarly, a slit 22 a is formed toextend in the Y direction, such that the slit 22 a communicates with thesecond room 28 and is opened downward. In other words, the slits 21 aand holes 22 a constitute delivery ports of the first and second nozzles21 and 22, respectively, which are arranged in two rows extending in theY direction and are opened closely to each other. The slits 21 a and 22a are arranged such that a position on the wafer W to which the solventAL is supplied is always located ahead of a position on the wafer W towhich the coating liquid BL is supplied, in the moving direction of thebeam 20.

Each of the slits 21 a and 22 a desirably has such a length that thecoating liquid BL or the solvent AL is delivered substantially all overthe entire width of a target region all at once in the Y direction. Thetarget region is a region to be coated with the coating liquid BL, onthe wafer W. In this embodiment, since the top surface of the wafer W isto be entirely coated with the coating liquid BL, the top surface of thewafer W can be defined as the target region as a whole.

Each of the delivery ports off the first and second nozzles 21 and 22may be formed of a number of holes arrayed at intervals in the Ydirection, in place of the slit. Further, in the embodiment, each of thedelivery ports of the first and second nozzles 21 and 22 is arrangedsuch that the coating liquid BL or the solvent AL is deliveredsubstantially all over the entire width, in the Y direction, of a targetregion on the wafer W, all at once. However, this is not essential,because the coating liquid BL and solvent AL can be diffused on thewafer W by means of rotation of the spin chuck 10. For example, each ofthe delivery ports of the first and second nozzles 21 and 22 may beformed of a short slit, or a tip opening of an ordinary nozzle pipeextending vertically.

The first room 27 of the movable beam 20 is connected through a tube 23to the tank 25 containing the coating or photo-resist liquid BL. Thephoto-resist liquid contains a solvent of, e.g., ketone series,cellosolve series, ester series, glycol series, or nitrogen containingseries, as the solution solvent of the liquid, and also contains aphotosensitive resin as the solute of the liquid. The second room 28 ofthe movable beam 20 is connected through a tube 24 and an open/closevalve 31 to the tank 26 containing the solvent AL. Although any solvent,which dissolves the coating or photo-resist liquid BL, can be used asthe solvent AL, the solvent AL desirably consists essentially of thesolution solvent of the coating or photo-resist liquid BL.

The tank 26 containing the solvent AL is connected to a nitrogen (N₂)gas source 32 through a flow control valve 33. The flow rate of the N₂gas is controlled by the control valve 33 to adjust pressure to the tank26, so that the solvent AL in the tank 26 is supplied onto the wafer Win a predetermined amount. The operation of the flow control valve 33 isautomatically controlled by a computer on the basis of a preset program.

Between the second tube 23 and the tank 20 of the coating liquid BL,there are an air operation valve 34, a bubble removing mechanism 35 forremoving bubbles in the coating liquid BL, a filter 36, and a flowcontroller 37, such as a bellows pump. The flow controller 37 isexpandable under control of a driving unit so as to send a predeterminedamount of the coating liquid BL to the first nozzle 21. Thepredetermined amount of the coating liquid BL sent from the flowcontroller 37 is supplied, e.g., dropped, as the coating liquid from thefirst nozzle 21 onto the center of the wafer W.

The flow controller 37 can control the supply rate of the photo-resistliquid down to a small amount as compared to a conventional technique.The driving unit has a ball screw member 38 formed of a screw connectedto the flow controller 37 and a nut engaging with the screw. The ballscrew member 38 is driven by a servo motor or stepping motor 39including a servo mechanism, which rotates the nut to linearly move thescrew.

In the above described system of supplying the photo-resist or coatingliquid, the delivery time of the coating liquid BL is controlled bymeans of the driving time of the stepping motor 39 of the flowcontroller 37. The delivery rate of the coating liquid BL is adjusted bymeans of driving conditions of the flow controller 37, such as drivingtime and driving speed, and opening/closing operation, i.e., ON/OFFoperation, of the valve 34 for opening/closing the coating liquidpassageway. Setting the driving time of the flow controller 37 and theON/OFF operation of the valve 34 are automatically controlled by thecomputer on the basis of a preset program.

The delivery time of the coating liquid BL may be controlled by anopening/closing operation of a variable orifice (not shown) arranged inthe first nozzle 21. Further, the coating liquid BL may be performed bypressurizing the tank 25 with N₂ gas. In this case, it is possible tocontrol the delivery time of the coating liquid BL by adjusting thepressure of the N₂ gas, without using the flow controller 37.

A temperature controlling mechanism 50 for setting the coating liquid BLand the solvent AL to a predetermined temperature, such as 23° C., isarranged on their supply lines. More specifically, as shown with phantomlines in FIG. 2, the temperature controlling mechanism 50 includes asupply line 51 for supplying a temperature-adjusted liquid CL, such asconstant temperature water, arranged to surround the first and secondtubes 23 and 24. A circulation line 52 is connected to the terminal endsof the supply line 51, and is provided with a circulation pump 53, andthermo-module 54 for keeping the temperature-adjusted liquid CL at aconstant temperature. With this arrangement, the coating liquid BL andsolvent AL flowing in the first and second tubes 23 and 24 are kept at apredetermined temperature, such as about 23° C., by the temperaturecontrolling mechanism 50.

As shown in FIG. 3, a tank 71 containing a solvent DL, such as thinner,for preventing the tip of the first nozzle 21 from drying, is arrangedin the waiting section 70. In place of the tank 71, as shown withphantom lines in FIG. 3, a bath 74 may be arranged to have an opening 73into which the lower portions of the first and second nozzles 21 and 22are inserted. Further, a member for spouting the solvent DL upward andwashing the tip of the first nozzle 21 may be arranged in the tank 71 orthe bath 74.

The scanning mechanism 40 has a column 42 which is movable in the Xdirection along a linear guide 41 arranged on an outer side of theapparatus body 60. The column 42 is provided with a holder 44 which ismovable in a vertical direction, i.e., Z direction, along a guide 43 onthe column 42. The movable beam 20 constituting the first and secondnozzles 21 and 22 is supported by the holder 4, such that the slits 21 aand 22 a at the bottom of the nozzles 21 and 22 are horizontal. Themovable beam 20 is moved in the X and vertical directions, which areperpendicular to the slits 21 a and 22 a, by a linear driver and anelevator, such as a ball screw, (not shown).

An explanation will be given about a coating method according to thepresent invention, using the coating apparatus having the abovedescribed structure.

First, the wafer W is transferred onto the spin chuck 10, which has beenkept stationary, by a transfer arm (not shown), and is attracted andheld on the spin chuck 10 by means of vacuum suction. On the other hand,the coating liquid, i.e., the photo-resist liquid left in the tip of thefirst nozzle 21 is delivered into the tank 71 and removed from the tipby means of a dummy dispense operation. Then, the movable beam 20 ismoved in the X direction while remaining parallel to the wafer Wthereabove. During this movement, onto the wafer W, the solvent AL isfirst supplied from the second nozzle 22, followed by the coating orphoto-resist liquid BL supplied from the first nozzle 21. By doing so,so-called wettability of the wafer W relative to the photo-resist liquidBL is increased, prior to the supply of the liquid BL, so that the waferW can be coated with the photo-resist liquid BL having a uniform andthin film thickness. Then, the spin chuck 10 is rotated along with thewafer W by the motor 14, to further increase the film thicknessuniformity of the photo-resist liquid.

The amount of the solvent AL supplied onto the opposite ends of thewafer W in the X direction may be set higher than those amounts suppliedonto the other portions of the wafer W, when the solvent AL and thecoating or photo-resist liquid BL are supplied. This adjustment can beperformed by increasing the supplied amount of the solvent AL by apredetermined amount at the start and end of the coating process, usingthe flow controller 33. With this operation, the coating or photo-resistliquid BL comes to have a lower viscosity and is more easily spread onthe opposite ends of the wafer W in the X direction, at which thesolvent AL is supplied more than at the other portions. As a result, thecoating liquid BL is prevented from forming a puddle, so that thecoating liquid film can have a uniform film thickness all over the topsurface of the wafer W. Further, although the coating liquid BL is aptto be delivered in a larger amount at the beginning of delivery, thisbeginning part of the coating liquid is removed by the dummy dispense,thereby performing the coating process with a stable delivery amount.

As described above, the solvent AL is first supplied onto the wafer W toincrease its wettability, and then the coating liquid BL is supplied, ina coating method according to the present invention, so as to coat thewafer W with the coating liquid BL having a uniform and thin filmthickness. Consequently, the coating method according to the presentinvention includes, in its concept, a pre-coating step of applying thesolvent AL and a main coating step of applying the coating liquid BL. Inthis embodiment, the pre-coating step and the main coating step aresimultaneously performed to overlap their effective periods of time witha slight time lag therebetween. However, the pre-coating step and themain coating step may be performed so as not to overlap their effectiveperiods of time at all. The coating method, using the coating apparatusshown in FIG. 2, can be modified as described in the following examples(1) to (3).

(1) After the solvent AL is supplied, the wafer W is rotated to diffusethe solvent AL all over the wafer W. Then, the coating liquid BL issupplied while the movable beam 20 is moved. In this case, the solventAL may be supplied only onto the center of the wafer W.

(2) In addition to the steps of the example (1), the wafer W is rotatedagain to cause the coating liquid film to be uniform after the coatingliquid BL is supplied.

(3) The solvent AL is supplied while the wafer W is rotated. Then, thecoating liquid BL is supplied while the movable beam 20 is moved. Then,the wafer W is rotated again to cause the coating liquid film to beuniform.

FIGS. 4 and 5 are views schematically showing the main part of a coatingapparatus according to another embodiment of the present invention.

In the above described embodiment, the first and second nozzles 21 and22 are moved in a plane of a constant height above the spin chuck 10. Inplace of this arrangement, the first and second nozzles 21 and 22 may becontrolled over their height, in light of the unevenness of the wafer W,i.e., the vertical positions of the top surface of the wafer W. For thispurpose, a height sensor 66 is used as means for detecting heights ofthe top surface of the wafer W, e.g., in a manner as shown in FIGS. 4and 5. The sensor 66 is attached to the bottom end of a support 65,which has a reversed L-shape and is arranged to extend toward ahead ofthe movable beam 20 from the column 42 of the scanning mechanism 40.

The sensor 66 is arranged such that a position on the wafer W which issensed by the sensor 66 is always located ahead of positions on thewafer W to which the coating liquid BL and the solvent AL are supplied,in the moving direction of the beam 20. Detected height signals alongthe center of the wafer W in the X direction, which are obtained by thesensor 66, are transmitted to a control section, such as a centralprocessing unit (CPU) 67. Control signals are sent to a nozzle elevator40A of the scanning mechanism 40 from the CPU 67, on the basis of theheight signals. By doing so, the height H of the first and secondnozzles 21 and 22 from the spin chuck 10 is continuously controlled, sothat the distance Gb between each of the delivery ports at the lowerends of the nozzles 21 and 22 and the top surface of the wafer W is keptconstant.

In order to detect the height of the wafer W and to control the distanceGb, a sensor or sensors of the point-sensing type may be used as theheight sensor 66. In this case, it is possible to detect the height ofone point every moment along the diameter of the wafer W, as describedabove, or to detect the height of three points every moment along thediameter of the wafer W and along lines one on either side of thediameter, in order to control the distance Gb on the basis of theaverage value of the three points. Alternatively, a sensor of the linesensor type may be used as the height sensor 66. In this case, it ispossible to detect the heights of plural points on the wafer W everymoment, in order to control the distance Gb on the basis of the averagevalue of the plural points.

The height sensor 66 may be supported by a scanning mechanism other thanthe scanning mechanism 40 for the nozzles. In this case, since thesensor 66 can perform a scanning operation independently, the height ofthe top surface of the wafer W may be detected prior to the coatingprocess. Further, a sensor of the line sensor type for detecting the topsurface of the wafer W may be arranged to be independently movable, sothat the height of the wafer W is detected while the sensor is moved inparallel to the wafer W. Furthermore, the movable beam 20 may be dividedinto a plurality of segments in the Y direction, which are independentlyadjustable in height, in order to control the distance Gb by thesegments.

In the structure shown in FIG. 2, the first and second nozzle 21 and 22are integrally formed to be one movable beam 20. However, the first andsecond nozzles 21 and 22 are not necessarily formed as one unit, but maybe independently formed and closely arranged.

Flattening means, such as a spatular member, for flattening the topsurface of the coating or photo-resist liquid, may be arranged close tothe slit 21 a of the first nozzle 21. With this arrangement, ridges onthe top surface of the delivered photo-resist liquid are forced to beflat, so that a uniform film thickness is obtained. In this case, thespatular member may be independently formed and attached to the movablebeams, or may be integrally formed with the movable beam 20.

In the structure shown in FIG. 2, the solvent AL and the photo-resistliquid BL are independently delivered. Instead, the solvent AL and thephoto-resist liquid BL may be delivered after they are mixed. Forexample, as shown in FIG. 6A, the slit 22 a of the second nozzle 22 isconnected to a halfway point of the passage to the slit 21 a of thefirst nozzle 21, and the solvent AL and the photo-resist liquid BL aredelivered through a common slit 20 a. With this arrangement, theviscosity, concentration, and the like of the photo-resist liquid BL canbe adjusted in the movable beam 20.

Further, a structure as shown in FIG. 6B may be adopted. Morespecifically, a bore 20 b is formed inside the lower part of a movablebeam 20 to accommodate the bottom openings of first and second nozzles21 and 22. A solvent reservoir 20 c is arranged in the bore 20 b tosurround an opening 20 d of the bore 20 b. The second nozzle 2 isinserted in the solvent reservoir 20 c. In this structure, the solventAL reserved in the solvent reservoir 20 c is evaporated to form asolvent atmosphere in the bore 20 b, so that the viscosity andconcentration of the photo-resist liquid can be adjusted beforedelivery. The solvent AL is delivered from the opening 20 d by itoverflowing from the solvent reservoir 20 c and flowing out of theopening 20 d.

A nozzle for spouting a solvent vapor toward the bottom of the movablebeam 20 may be arranged so as to form an atmosphere full of the solventvapor at a position facing the wafer W, while the photo-resist liquid BLis supplied. Further, the entire top surface of the wafer W may becovered with the solvent vapor, while the photo-resist liquid BL issupplied.

The present invention may be applied to a coating apparatus of adeveloping liquid other than the photo-resist liquid. In this case, adeveloping liquid and water are defined as the coating liquid BL and thesolvent AL, respectively. More specifically, the wafer W is first coatedwith water used as the solvent AL to increase wettability of the wafer Wrelative to the developing liquid, and is then coated with developingliquid used as the coating liquid BL, thereby forming a uniform film ofthe developing liquid on the wafer W. Note that in a coating apparatusof the developing liquid, a drying mechanism is necessary for drying thesurface of the wafer W after it is coated with the developing liquid.For example, where the spin chuck 10 is used as supporting means of thewafer W, the drying step can be performed by a so-called spin dryingoperation, in which the wafer W is rotated by the spin chuck 10 at ahigh speed. Instead, it is possible to use an air nozzle 80 which hasspouting holes along the entire length of the movable beam 20 and isarranged on the beam 20. In this case, after performing the coatingprocess, the movable beam 20 is again moved in the X direction above thewafer W so as to spout air onto the entire top surface of the wafer W.By doing so, the surface of the wafer W is dried by a so-called airknife operation.

A coating apparatus according to the present invention may be used as anindependent coating apparatus for coating a semiconductor wafer or anLCD substrate with a developing liquid or a photo-resist liquid, or maybe used as a unit incorporated in a coating and developing system asshown in FIG. 7.

The coating and developing system shown in FIG. 7 has a loading section101, a first processing block 91 next to the loading section 101, and asecond processing block 92 connected to the first processing block 91through an interface section 93. The loading section 101 is used fortransferring semiconductor wafers W to be processed into and out of thesystem.

In the first processing block 91, a brush scrubbing apparatus 102 forbrush-scrubbing and washing a wafer W is arranged adjacent to theloading section 101. A jet-water washing apparatus 103 for washing thewafer W by means of jet water of a high-pressure is arranged next to thebrush scrubbing apparatus 102. Further, an adhesion apparatus 104 forsubjecting the surface of the wafer W to a hydrophobic treatment isarranged next to the jet-water washing apparatus 103. A coolingapparatus 105 for cooling the wafer W down to a predeterminedtemperature is arranged under the adhesion apparatus 104. A photo-resistcoating apparatus 106 is arranged to face the apparatuses 102 to 105through a wafer transfer passage. The photo-resist coating apparatus 106has a coating mechanism for coating the wafer W with a photo-resist, anda coating film removing mechanism for removing an unnecessary part ofthe photo-resist film on the marginal region of the wafer W. The coatingmechanism of the photo-resist coating apparatus 106 has a structure, asdescribed with reference to FIGS. 1 to 3. A wafer transfer arm 111 a isarranged on the wafer transfer passage to be movable along the passage.

In the second processing block 92, a heating apparatus 108 is arrangedfor heating the wafer W before and after the photo-resist coatingprocess, to perform pre-baking and post-baking treatments. A developingapparatus 109 is arranged to face the heating apparatus 108 through thewafer transfer passage. The developing apparatus 109 has members forsubjecting the wafer, which has been light-exposed, to a developingtreatment, and for rinsing the developed photo-resist pattern. A wafertransfer arm 111 b is arranged on the wafer transfer passage to bemovable along the passage. A light-exposing apparatus (not shown) isconnected to the second processing block 92 on the far side, forprojecting a circuit pattern of chips, which are to be formed on thewafer W, onto photo-resist film on the wafer W.

In the coating and developing system having the above describedstructure, an unprocessed wafer W is received by the wafer transfer arm111 a from the loading section 101, and is transferred into the brushscrubbing apparatus 102. After being subjected to a brush scrubbing andwashing treatment in the brush scrubbing apparatus 102, the wafer W iscleaned by means of jet water of a high-pressure in the jet-waterwashing apparatus 103. After being cleaned, the wafer W is subjected toa hydrophobic treatment in the adhesion apparatus 104. Then, the wafer Wis cooled in a cooling apparatus 105, and is transferred into thephoto-resist coating apparatus 106. In the coating apparatus, thephoto-resist liquid is applied onto the wafer W to form a coating filmin accordance with the above described sequence, and then an unnecessarypart of the photo-resist film on the marginal region of the wafer W isremoved. As a result, when being delivered therefrom, the wafer W has nophoto-resist film on its edge, so that no photo-resist film adheres tothe transfer arms 111 a and 111 b.

Then the photo-resist film left on the wafer is subjected to a bakingtreatment by means of heating in a heating apparatus 108, and is exposedto light with a predetermined pattern in the light-exposing apparatus(not shown). After being light-exposed, the wafer W is transferred tothe developing apparatus 109, and is subjected to a developing treatmentwith a developing liquid. Then, the developing liquid is washed out by arinsing liquid, so that the developing treatment is completed. After thedeveloping treatment, the wafer W is transferred into a cassette (notshown) in the loading section 101, and is then transferred therefrom tothe next process.

In the above described embodiment, the present invention is applied to acoating apparatus for coating a semiconductor wafer or an LCD substratewith a coating liquid, such as a developing liquid or a photo-resistliquid. The present invention, however, may be applied to a coatingapparatus of another type, e.g., for coating another target substrate,such as a CD, with a coating liquid, or for coating an electric boardwith a green film. Further, another coating liquid, such as apolyimide-based coating liquid (PIQ) or a coating liquid containing aglass component (SOG) may be used.

Additional advantages and modifications will readily occur to thoseskilled in the art. Therefore, the invention in its broader aspects isnot limited to the specific details and representative embodiments shownand described herein. Accordingly, various modifications may be madewithout departing from the spirit or scope of the general inventiveconcept as defined by the appended claims and their equivalents.

What is claimed is:
 1. An apparatus for coating a target region of asubstrate selected from the group consisting of a semiconductor waferand a liquid crystal display substrate with a photo-resist, comprising:a support configured to support said substrate substantially horizontal;a solvent supply port configured to supply a solvent for saidphoto-resist from a source of solvent into a first area above thesubstrate for deposit onto said target region of said substratesupported by said support; a photo-resist supply port configured tosupply said photo-resist from a source of photo-resist into a secondarea above the substrate for deposit onto said target region of saidsubstrate supported by said support, the photo-resist supply port beingseparated from the solvent supply port by a distance that substantiallyprevents said solvent and said photo-resist from being in contact whensupplied into the first and second areas above the substrate; and ashifting member configured to move said ports relative to said substratesupported by said support, in a straight line direction from a locationadjacent to a first end portion of said target region to a locationadjacent to a second end portion of said target region, such that saidphoto-resist supply port is moved along with but immediately behind saidsolvent supply port in said straight line direction, while said solventand said photo-resist are being supplied, wherein said solvent supplyport and said photo-resist supply port are further configured torespectively supply said solvent and said photo-resist substantially outof contact into the first and second areas above the substratesubstantially across a full width dimension of said substrate all atonce, said full width dimension of said substrate being measured in adirection perpendicular to said straight line direction.
 2. Theapparatus according to claim 1, wherein said support is capable ofrotating said substrate in a horizontal plane.
 3. The apparatusaccording to claim 1, comprising a member configured to supply an amountof said solvent onto each of said first and second end portions of saidtarget region that is larger than an amount of said solvent suppliedonto any other portion of said target region.
 4. The apparatus accordingto claim 1, comprising a sensor configured to detect height variationsof a surface of said target region facing said ports, and a memberconfigured to cause a distance between said surface of said targetregion facing said ports and said ports to be maintained constant basedon the height variation detected by said sensor.
 5. The apparatusaccording to claim 4, wherein said sensor is moved by said shiftingmember along with said ports such that a position on said target regionbeing detected by said sensor is located ahead of a position on saidtarget region being supplied with said solvent, in said straight linedirection.
 6. The apparatus according to claim 1, wherein said shiftingmember and said distance between said solvent supply port and saidphoto-resist supply port are designed such that said solvent is firstsupplied onto said target region to increase wettability of said targetregion relative to said photo-resist by said solvent, and then saidphoto-resist is supplied onto said target region.
 7. The apparatusaccording to claim 1, further comprising a temperature control sectionconfigured to control temperatures of first and second lines, whichsupply said solvent and said photo-resist to said solvent supply portand said photo-resist supply port, respectively.
 8. The apparatusaccording to claim 7, wherein said temperature control section isconfigured to adjust said solvent and said photo-resist in said firstand second lines to substantially the same temperature by a commonthermo-medium.